Interlingual word mapping

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Interlingual word mapping

• MTP I Stage Project Presentation
• Guided by- Presented by-
• Prof. Pushpak Bhattacharyya
  Abhijeet Padhye
• Department of Computer Science and Engineering
• Indian Institute of Technology, Bombay

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Presentation pathway

1. Motivation
2. Introduction
3. Introduction to Transliteration
4. Syllables and their structure types
5. Sonority Theory
6. Relation between Sonority and Syllables
7. What is Schwa?
8. A Sonority theory based Syllabification module
9. Results obtained
10. References

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Motivation

• Language an integral part of society
• Each has its specific structure and rules
• Some basic concepts common to all
• Helpful in processes like transliteration
  ultimately leading to better CLIR.
• We are trying to exploit them for process of
  syllabification

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Problem statement

• To study some Phonological similarities
  between English, Hindi and Marathi and exploit
  them in order to achieve the goal of
  transliteration with high accuracy so as to be
  able to tackle problems like OOV words during
  Cross-Lingual Information Retrieval.

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introduction

• Concepts being emphasized
• Transliteration
• Theory of Syllables
• Sonority Theory
• Their relation
• Theory of Schwa Schwa deletion
• Mainly based on the properties of Sound
• Driving force behind word pronunciation in any
  language

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Introduction to transliteraton

• A process of phonetically translating named
  entities like proper nouns from a source language
  to a target language.1
• The process of transliteration should be as
  accurate as possible.
• Faces the problem of multiple variants of words.

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Proposed transliteration model
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Basic of syllables

• Syllable is a unit of spoken language
  consisting of a single uninterrupted sound formed
  generally by a Vowel and preceded or followed by
  one or more consonants.
• Vowels are the heart of a syllable(Most Sonorous
  Element)
• Consonants act as sounds attached to vowels.

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Syllable structure

• A syllable consists of 3 major parts-
• Onset (C)
• Nucleus (V)
• Coda (C)
• Vowels sit in the Nucleus of a syllable
• Consonants may get attached as Onset or Coda.
• Basic structure - CV

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Possible syllable structures

• The Nucleus is always present
• Onset and Coda may be absent
• Possible structures
• V
• CV
• VC
• CVC

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syllable theories

• Prominence Theory
• E.g. entertaining /ent?te?n??/
• The peaks of prominence vowels /e ? e? ?/
• Number of syllables 4
• Chest Pulse Theory
• Based on muscular activities
• Sonority Theory
• Based on relative soundness of segment within
  words

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Introduction to sonority theory

• The Sonority of a sound is its loudness
  relative to other sounds with the same length,
  stress and speech.
• Languages have sounds associated with them
• Some sounds are more sonorous
• Words in a language can be divided into syllables
• Sonority theory distinguishes syllables on the
  basis of sounds.

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Sonority hierarchy

• Defined on the basis of amount of sound
  associated
• The sonority hierarchy is as follows-
• Vowels (a, e, i, o, u)
• Liquids (y, r, l, v)
• Nasals (n, m)
• Fricatives (s, z, f,..sh, th etc.)
• Affricates (ch, j)
• Stops (b, d, g, p, t, k)

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Sonority scale

• Obstruents can be further classified into-
• Fricatives
• Affricates
• Stops

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Sonority theory syllables

• A Syllable is a cluster of sonority, defined by
  a sonority peak acting as a structural magnet to
  the surrounding lower sonority elements.
• Represented as waves of sonority or Sonority
  Profile of that syllable
• Nucleus
• Onset Coda

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Sonority sequencing principle

• The Sonority Profile of a syllable must rise
  until its Peak(Nucleus), and then fall.
• Peak
• (Nucleus)
• Onset Coda

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examples

• ABHIJEET
• Sonority Profile 1
• A I E E
• H J
• B T
• Sonority Profile 2
• A I E E
• H J
• B T

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Maximal onset principle

• The Intervocalic consonants are maximally
  assigned to the Onsets of syllables in conformity
  with Universal and Language-Specific Conditions.
• Determines underlying syllable division
• Example
• DIPLOMA
• DIP LO MA DI PLO MA

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The concept of schwa

• First alphabet of IAL a
• Unstressed and Toneless neutral vowel
• Sanskrit is phonetically perfect no neutral
  vowels
• Hindi, Bengali etc. allow schwa to be neutral
• Some schwas deleted and some are not
• Schwa deletion important issue for grapheme to
  phoneme conversion

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Schwa deletion contexts

1. Saphalya and Amantrana
2. Priya and Tritiya
3. Kavya and Ashva
4. Badhai
5. Samuha and Chehara
6. Badara and Kalama
7. Kalama and Banda

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A sonority-theoretic model

• Developed completely in Java
• Platform independent
• Tries to perform syllabification of words
• Rides on the concepts of Sonority theory mainly
  sonority sequencing principle
• Makes use of Javas Hashmap utility to save
  execution time.

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Technical overview

• Consists of three major functions-
• SonorityHierarchy()
• syllabify(String word)
• accuracy()
• Delete_schwa() Under Development
• Stores and references the Sonority hierarchy from
  the hashmap
• Tries to find the syllable boundaries according
  to their sonority profile
• Tries to delete schwas present in the input

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results

• Syllabification and PRR generation modules
  implemented
• Number of manually syllabified words 27614
• No. of words fed as input 27614
• No. of words correctly syllabified 26253
• Accuracy obtained 95.86 for English and about
  70 for Hindi
• Accuracy of Schwa deletion in English 77
• Schwa deletion for Hindi is under developement

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Problems and future work

• Problems faced
• First rule-based implementation failed
• Some specific consonant and vowel clusters still
  result in erroneous syllabification
• Future work
• Schwa deletion for Hindi and Marathi
• Implementation of Maximal Onset First principle
• Packaging the above implementation in a stable
  transliteration module to be used further in CLIR

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References

1. Giegerich, H. J. 1992. English Phonology. An
   Introduction.
2. Kahn, Daniel. 1976. Syllable-based
   generalizations in English phonology.
3. Lass, Roger. Phonology An Introduction to Basic
   Concepts. Cambridge University Press, 1984